In the lumber industry, a number of apparatuses have been employed to cut timber (hereinafter referred to as a cant) into usable pieces for subsequent operations or usage. Frequently, a wood cant must be cut into fairly thin but elongated pieces and typically band saws are used to accomplish this operation. In conventional band saws, such as represented by U.S. Pat. No. 4,061,066, issued Dec. 6, 1977, U.S. Pat. No. 6,745,644, issued Jun. 8, 2004, U.S. Pat. No. 5,557,989, issued Sep. 24, 1996 and U.S. Pat. No. 5,819,613, issued Oct. 13, 1998, an endless band saw is looped around an idler pulley wheel and a drive wheel which is motor driven and operated at high speed to rotate the drive wheel and, hence, the band saw over the pulley wheel while cants or wooden pieces are transported by a conveyor or manually against the cutting teeth of the band saw. Tension on the band saw is maintained by adjusting the distance between the central axis of rotation of the pulley and the drive wheel. The maintenance of the proper tension in the band saw loop is critical to efficient cutting operation and the avoidance of damage to the band saw loop. In particular, an improper low tension will result in wastage of the wood product since vibration of the loop will increase the size of the kerfs or cut made in the wood and can lead to breakage of the band itself.
My earlier U.S. Pat. No. 8,151,680 (Pollard) discloses an air bearing being use in a band saw. Different sized bearings are used to provide different locations for the cutting sections of the band saw.